1/*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef GrGLVertexArray_DEFINED
9#define GrGLVertexArray_DEFINED
10
11#include "GrGpuObject.h"
12#include "GrTypesPriv.h"
13#include "gl/GrGLDefines.h"
14#include "gl/GrGLFunctions.h"
15
16#include "SkTArray.h"
17
18class GrGLVertexBuffer;
19class GrGLIndexBuffer;
20class GrGpuGL;
21
22struct GrGLAttribLayout {
23    GrGLint     fCount;
24    GrGLenum    fType;
25    GrGLboolean fNormalized;
26};
27
28static inline const GrGLAttribLayout& GrGLAttribTypeToLayout(GrVertexAttribType type) {
29    SkASSERT(type >= 0 && type < kGrVertexAttribTypeCount);
30    static const GrGLAttribLayout kLayouts[kGrVertexAttribTypeCount] = {
31        {1, GR_GL_FLOAT, false},         // kFloat_GrVertexAttribType
32        {2, GR_GL_FLOAT, false},         // kVec2f_GrVertexAttribType
33        {3, GR_GL_FLOAT, false},         // kVec3f_GrVertexAttribType
34        {4, GR_GL_FLOAT, false},         // kVec4f_GrVertexAttribType
35        {4, GR_GL_UNSIGNED_BYTE, true},  // kVec4ub_GrVertexAttribType
36    };
37    GR_STATIC_ASSERT(0 == kFloat_GrVertexAttribType);
38    GR_STATIC_ASSERT(1 == kVec2f_GrVertexAttribType);
39    GR_STATIC_ASSERT(2 == kVec3f_GrVertexAttribType);
40    GR_STATIC_ASSERT(3 == kVec4f_GrVertexAttribType);
41    GR_STATIC_ASSERT(4 == kVec4ub_GrVertexAttribType);
42    GR_STATIC_ASSERT(SK_ARRAY_COUNT(kLayouts) == kGrVertexAttribTypeCount);
43    return kLayouts[type];
44}
45
46/**
47 * This sets and tracks the vertex attribute array state. It is used internally by GrGLVertexArray
48 * (below) but is separate because it is also used to track the state of vertex array object 0.
49 */
50class GrGLAttribArrayState {
51public:
52    explicit GrGLAttribArrayState(int arrayCount = 0) {
53        this->resize(arrayCount);
54    }
55
56    void resize(int newCount) {
57        fAttribArrayStates.resize_back(newCount);
58        for (int i = 0; i < newCount; ++i) {
59            fAttribArrayStates[i].invalidate();
60        }
61    }
62
63    /**
64     * This function enables and sets vertex attrib state for the specified attrib index. It is
65     * assumed that the GrGLAttribArrayState is tracking the state of the currently bound vertex
66     * array object.
67     */
68    void set(const GrGpuGL*,
69             int index,
70             GrGLVertexBuffer*,
71             GrGLint size,
72             GrGLenum type,
73             GrGLboolean normalized,
74             GrGLsizei stride,
75             GrGLvoid* offset);
76
77    /**
78     * This function disables vertex attribs not present in the mask. It is assumed that the
79     * GrGLAttribArrayState is tracking the state of the currently bound vertex array object.
80     */
81    void disableUnusedArrays(const GrGpuGL*, uint64_t usedAttribArrayMask);
82
83    void invalidate() {
84        int count = fAttribArrayStates.count();
85        for (int i = 0; i < count; ++i) {
86            fAttribArrayStates[i].invalidate();
87        }
88    }
89
90    void notifyVertexBufferDelete(GrGLuint id) {
91        int count = fAttribArrayStates.count();
92        for (int i = 0; i < count; ++i) {
93            if (fAttribArrayStates[i].fAttribPointerIsValid &&
94                id == fAttribArrayStates[i].fVertexBufferID) {
95                fAttribArrayStates[i].invalidate();
96            }
97        }
98    }
99
100    /**
101     * The number of attrib arrays that this object is configured to track.
102     */
103    int count() const { return fAttribArrayStates.count(); }
104
105private:
106    /**
107     * Tracks the state of glVertexAttribArray for an attribute index.
108     */
109    struct AttribArrayState {
110            void invalidate() {
111                fEnableIsValid = false;
112                fAttribPointerIsValid = false;
113            }
114
115            bool        fEnableIsValid;
116            bool        fAttribPointerIsValid;
117            bool        fEnabled;
118            GrGLuint    fVertexBufferID;
119            GrGLint     fSize;
120            GrGLenum    fType;
121            GrGLboolean fNormalized;
122            GrGLsizei   fStride;
123            GrGLvoid*   fOffset;
124    };
125
126    SkSTArray<16, AttribArrayState, true> fAttribArrayStates;
127};
128
129/**
130 * This class represents an OpenGL vertex array object. It manages the lifetime of the vertex array
131 * and is used to track the state of the vertex array to avoid redundant GL calls.
132 */
133class GrGLVertexArray : public GrGpuObject {
134public:
135    GrGLVertexArray(GrGpuGL* gpu, GrGLint id, int attribCount);
136
137    /**
138     * Binds this vertex array. If the ID has been deleted or abandoned then NULL is returned.
139     * Otherwise, the GrGLAttribArrayState that is tracking this vertex array's attrib bindings is
140     * returned.
141     */
142    GrGLAttribArrayState* bind();
143
144    /**
145     * This is a version of the above function that also binds an index buffer to the vertex
146     * array object.
147     */
148    GrGLAttribArrayState* bindWithIndexBuffer(const GrGLIndexBuffer* indexBuffer);
149
150    void notifyIndexBufferDelete(GrGLuint bufferID);
151
152    void notifyVertexBufferDelete(GrGLuint id) {
153        fAttribArrays.notifyVertexBufferDelete(id);
154    }
155
156    GrGLuint arrayID() const { return fID; }
157
158    void invalidateCachedState();
159
160    virtual size_t gpuMemorySize() const SK_OVERRIDE { return 0; }
161
162protected:
163    virtual void onAbandon() SK_OVERRIDE;
164
165    virtual void onRelease() SK_OVERRIDE;
166
167private:
168    GrGLuint                fID;
169    GrGLAttribArrayState    fAttribArrays;
170    GrGLuint                fIndexBufferID;
171    bool                    fIndexBufferIDIsValid;
172
173    typedef GrGpuObject INHERITED;
174};
175
176#endif
177